Mobile devices are small electronic computing devices often referred to as personal digital assistants. One such mobile device is the Handheld PC (or "H/PC") based on and including the Windows CE operating system sold by Microsoft Corporation of Redmond, Wash. While a wide variety of computing tasks and applications can be performed by such mobile devices, personal information managers (PIMs) are particularly well suited to mobile devices.
PIMs typically comprise applications which enable the user of the mobile device to better manage scheduling and communications, and other such tasks. Some commonly available PIMs include scheduling and calendar programs, task lists, address books, and electronic mail (e-mail) programs. Some commonly commercially available PIMs are sold under the brand names Microsoft Schedule+ and Microsoft Outlook and are commercially available from Microsoft Corporation of Redmond, Wash.
It is also common for mobile devices to be used in conjunction with one or more desktop computers. For example, the user of a mobile device may also have access to, and use, a desktop computer at work, at home, or both. A user may typically run the same types of PIMs on both the desktop computer and the mobile device (although the particular versions of the PIMs may be somewhat different from the desktop computer to the mobile device). Thus, it is quite advantageous for the mobile device to be designed to be coupleable to the desktop computer to exchange information with, and share information with, the mobile device.
The user may also typically make changes to the PIMs both on the mobile device, and at the desktop. Therefore, it is advantageous for the PIMs on both the mobile device and the desktop to contain the most up-to-date information, regardless of whether recent changes to the PIMs have been made on the mobile device or the desktop computer. The process of coupling the mobile device with the desktop computer, and integrating the information stored by the PIMs on the mobile device and the desktop computer such that the two contain the same updated information is referred to as synchronization.
Conventional PIMs which support electronic mail messaging commonly provide the ability for the sender of an electronic mail message to electronically attach a document or other file to the electronic mail message such that the attachment is sent along with the electronic mail message to the recipient of the electronic mail message. Some prior mobile devices have been designed to allow the synchronization of electronic mail messages. However, to date, that synchronization has been directed to the electronic mail messages only, without the attachments. In other words, during synchronization of electronic mail messages, the attachments have conventionally been stripped out of the electronic mail transfer such that the user of the mobile device only receives the electronic mail message itself, with the attachments being stripped out of that message and inaccessible by the user of the mobile device.
A number of significant obstacles present themselves when dealing with the transfer of electronic mail messages in the environment which defines the interaction between the desktop computer and a mobile device. First, typical mobile devices have significantly limited amounts of memory relative to a desktop computer. Attachments supported by conventional PIMs may commonly not simply be text files, or documents, but may also be more memory intensive files, such as drawings, graphs, charts, and so on. Therefore, synchronization of attachments to electronic mail messages presents difficult questions with respect to memory capacity. Also, providing an adequate electronic mail address book without dominating mobile device memory presents problems.
Further, many attachments may be unneeded by the user of the mobile device, unless the user is at the desktop. In other words, the user may not desire to (and indeed may have no use to) observe many attachments, unless the user is at the desktop where the user can view the attachments and act on the attachments in that environment.
In addition, some users may receive electronic mail messages from sources which the user does not desire to synchronize with the desktop computer. For example, if the ability were provided to couple the mobile device to more than one other computing device, the user may not wish to synchronize all information on both other computing devices and the mobile device. Thus, appropriate discrimination among messages presents problems as well.